1. Field of the Invention (Technical Field)
In the parent application, the invention is directed to methods and apparatus for forming, sizing and interconnecting duct work systems on site, including pre-insulated components and connectors for transporting fluids. More particularly, the invention is a device which combines a flat panel manufactured with an intermediate insulation layer sandwiched between two outside waterproof sheets, take-off apparatuses of two part construction and pre-insulted connector articles including matched transition components adapted to form an insulated duct system sized on-site.
In the present application, the invention is directed to an insulated air duct system for transferring a volume of fluid in a warm air heating and air conditioning system without employing external insulation or structural support members, otherwise required to support and insulate duct apparatus, comprising a plurality of lightweight duct modules in combination with take-off connectors, each formed on-site from rigid fibrous glass board (RFGB) with reinforced facing each duct module comprising structural support means for providing inherent structural strength to each duct module and including one or more insulated fitting devices for coupling air duct system components together.
2. Background Art
There is a well recognized need for ease of forming air duct work on site, particularly duct work requiring insulation installed in residential buildings. Applicant is aware of prior art devices that have attempted to solve this need by employing a duct board of sandwiched construction for constructing ducts.
In U.S. Pat. No. 5,219,403 to Murphy, there is shown a distribution box, and a rectangular duct line having an intermediate foam core sandwiched between inner and outer plastic layers. Corner molding slots are provided to connect two adjacent duct board walls along its length. The limitations of Murphy result from the inherent structural weakness of foam core duct board walls requiring additional exterior structural support resulting in difficult and slow assembly, as well as structurally weak corner joints. Also Murphy does not teach a simple and effective means of joining duct lines, nor internally insulated couplings.
The present invention overcomes the limitations expressed above of the prior technology, by employing the advantageous characteristics of an insulated air duct system comprising a plurality of lightweight, insulated duct modules in combination with take-off connectors, each duct module comprising duct walls joined by corner members with comprising rigid fibrous glass (RFGB) with reinforced facing, formed on-site, having inherent structural strength such that each duct module is self supporting and including one or insulated improved fitting devices for joining duct modules and for coupling insulated components.